The term “endoscope” is generally used to designate a flexible or rigid probe for inserting into a dark cavity and enabling its user to observe a target situated inside the cavity by means of an eyepiece. For this purpose, an endoscope includes a device for illuminating the target and an optical device for providing the user with an optical image of the target. The optical device comprises a distal objective lens, a rigid image transport device constituted by a series of lenses or a flexible image transport device constituted by an ordered bundle of optical fibers, and a proximal eyepiece through which the user can observe visually the image of the target. The lighting device is generally constituted by a bundle of lighting fibers with the distal end thereof being appropriately disposed close to the distal objective lens to light the target when the proximal end of the bundle is connected to a light generator.
The term “videoendoscope” is used to designate a flexible or rigid probe enabling its user to observe on a video screen the image of a target situated in a dark cavity. To this end, a videoendoscope generally comprises the following elements:                a distal endpiece housing an optoelectronic device comprising in particular an objective lens and a charged-coupled device (CCD) sensor having a sensitive surface on which the objective lens forms an image of the target;        a flexible inspection tube whose distal end is secured to the distal endpiece;        a control handle secured to the proximal end of the inspection tube;        a flexible umbilical cable for connection purposes whose distal end is secured to the control handle and whose proximal end is designed to be connected to an external unit containing a light generator and an electrical power supply;        a bundle of lighting fibers housed in the umbilical cable, in the control handle, and in the inspection tube, with the distal end of the bundle housed in the distal endpiece serving to light the target when the proximal end of the bundle is connected to a light generator;        a video processor electrically connected to the CCD sensor, with synchronization thereof being controlled as a function of the length of the electrical cable connecting it to the CCD sensor;        a video screen connected to the video processor; and        a control panel enabling the operation of the video processor and possibly also that of the video screen to be adjusted.        
Flexible videoendoscopes also have an articulated bending section at the distal end enabling the distal endpiece of the probe to be steered, the control handle then generally including mechanical or electrochemical control means enabling the bending section to be actuated. The electromechanical control means for the distal bending section generally comprise two motors housed in the control handle and actuating respective pulleys connected by cables to the distal bending section, the motors being controlled by means of a joystick integrated in the control panel.
Videoendoscopes of recent design can also be associated with a digital system for freezing, processing, and storing images suitable for being controlled directly by the control panel of the videoendoscope.
In the architectures used by various present-day videoendoscope manufacturers:                the video processor is integrated either in the control handle, or in the connection unit of the probe, or in the external unit containing the light generator;        the video monitor may be integrated in the control handle or may be connected to the external unit; and        the control panel of the video processor and of the video monitor may be integrated either in the control handle, or in the external unit.        
The control handle of the videoendoscope constituting the subject matter of the present invention contains the video monitor, the control panel for the video processor, and possibly also the steering controls, the video processor being housed in a connection unit constituting the proximal end of the umbilical cable, or preferably being housed in the control handle.
Control handles of this type are usually in the form of an elongate unit secured to a video monitor disposed transversely on said unit. The inspection tube is secured to the distal end of the unit while the umbilical cable is secured to its proximal end. Generally, the control panel is integrated in the control unit.
As a result, the dimensions of the video monitor are necessarily small so as to avoid making the handle too heavy and unbalancing its center of gravity. It is therefore often necessary to connect the videoendoscope to an external video monitor of larger dimensions, thereby directly affecting the independence and the mobility of the equipment.
In addition, the user is hindered by the umbilical cable secured to the proximal end of the control handle.
One such control handle is described in U.S. Pat. No. 6,315,712 filed by the Applicant, and in U.S. Pat. No. 5,373,317.
U.S. Pat. No. 4,539,586 describes a connection module for a videoendoscope probe enabling the probe to be connected to an external unit that is specially adapted, including in particular a light generator, a video processor, and an electrical power supply. That connection module comprises electronic circuits such as amplifiers and clock delay compensators which are adjusted as a function of the length of the probe, so as to enable probes of different lengths to be connected thereto.
European patent application No. 0 587 514 also describes a connection module for a videoendoscope probe, the module including a video processor adjusted as a function of the length of the probe, said connection module being pluggable in a specific external unit housing a light generator and an electrical power supply.
The videoendoscopes described in those documents require the user to acquire a specifically-adapted external unit that includes a light generator and an electrical power supply presenting characteristics that are likewise specific. However, it often happens that the users of such videoendoscope probes already have light generators for such probes. In addition, it is preferable to be able to have a plurality of light generators available so as to be able to continue using a probe even in the event of one of the generators breaking down.
An example of an electromechanical device for controlling distal steering is described for example in U.S. Pat. No. 4,941,454. That electromechanical device comprises two servo-motors each actuating a respective pulley driving a pair of cables whose two ends are fixed to the distal bending section in order to transmit movements of the pulley thereto, thereby steering the articulated distal bending section in a plane, with the two planes in which the distal bending section is steered respectively by the two servo-motors being perpendicular to each other.
That device also includes a servo-motor control circuit generating a train of pulses for each servo-motor with the width of the pulses being adjusted by means of a potentiometer. The two potentiometers are actuated mechanically by the movements in two perpendicular planes of a joystick actuated manually by the user.
Because a joystick is used to actuate the potentiometers, prolonged manual action on the joystick leads to permanent deflection thereof and thus to a permanent specific steered configuration of the remote bending section. However as soon as the user releases the joystick, it returns to its neutral position, and the same applies to the bending section.
In addition, it is found that that solution does not enable the angular positions of the pulleys to be determined. That drawback is particularly troublesome, given that the user cannot perceive naturally the orientation of the bending section whose movements are controlled by the joystick.
In principle, when the joystick is in its middle position the bending section takes up a neutral orientation, i.e. it lies on the axis of the distal end of the probe. Consequently, if the joystick presents a permanent deflected position, the bending section likewise presents a permanent deflected orientation, which makes such a device awkward to use.
U.S. Pat. No. 5,658,238 describes another example of an electromechanical device for controlling a distal bending section, the device comprising direct current (DC) motors controlled by control buttons, the controlling electronics of that device being disposed in an external unit. That device requires encoders to be provided for determining the respective angular positions of the motors, and thus electronic servo-control of said angular positions.
Endoscopes and videoendoscopes presenting a flexible inspection tube are generally stored by winding the inspection tube around a drum.
U.S. Pat. No. 4,913,369 describes such a drum mounted to turn on a base and comprising a foam hub presenting housings for storing the distal endpiece of the probe and the connector situated at the proximal end, said housings being closed by a side cover. As a result such a drum must be removed from its storage case before it is possible to use the probe.
European patent No. 0 276 139 and U.S. application Ser. No. 2002/0 032 365 describe storage drums for videoendoscope probes, with the probes being wound around said drums beginning by the distal end, the hub of a drum including means for connecting the proximal end of the probe to an electrical power supply and a light source. That enables the probe to be used without it being necessary to unwind it completely from the drum. Nevertheless, that solution presents the drawback of requiring the light source and the video processor to be integrated in the hub of the drum and rotary electrical connectors to be provided for powering the probe, where such connection means are very expensive, not very reliable in the long term, and give rise to electrical losses. In addition, that solution makes the probe unusable with a different storage case.
Furthermore, U.S. Pat. No. 5,314,070 describes a storage case for a videoendoscope or endoscope inspection tube comprising a spiral-wound storage tube in which the inspection tube is engaged. As a result, on each insertion and extraction into and from the storage case, the inspection tube and in particular its distal endpiece rubs against the inside wall of the storage tube. Once a certain length of the inspection tube has been engaged in the storage tube, the force needed to overcome friction forces becomes very large and there is a danger of damaging the inspection tube, and in particular the junction between the inspection tube and the control handle, by exaggerated twisting of the inspection tube. This risk of twisting requires the sheath of the inspection tube to be reinforced, at least in the vicinity of the control unit, thus leading to extra cost. Furthermore, that solution is not suitable for endoscopes having an inspection tube that is long, in particular longer than 6 meters (m).